Calculate motor efficiency, Electrical Engineering

Assignment Help:

1. A self excited shunt generator supplies a load of 12.5 kw at 125 volts. The field resistance is 25 ohms and the armature resistance is 0.2 ohms. The total voltage drop because of brush current and armature reaction at this load is 3 volts. Calculate the induced armature voltage.

2. A 6 pole lap-wound armature having 720 conductors, rotates in a field of 20.35 mWb. (a) If the induced current is 72 A, what is the torque developed by armature? (b) If the induced armature voltage is 410V, what is the motor speed?

3. A shunt motor runs at 1100 rpm at 230v and draws a line current of 40 A. The output power(at the shaft) is 10.8 h.p. The various losses are core loss, 200W: friction and windage loss 140W: electrical loss due to brush contact, 32W: stray load loss, 31W. The armature and field-current resistance are 0.2 ohms and 220 ohms respectively. Calculate (a) motor efficiency, (b) the speed if the output power is reduced by 50%.

4. A 4 pole motor is lap wound with 728 conductors and has a flux of 25 mWb per pole. The armature takes 50 A in current: the resultant demagnetizing effect due to armature reaction reduces the air gap flux by 5%. Calculate the developed torque.

5. One of three fuses protecting a 3-phase electric heater rated at 200kW, 600 V is removed so as to reduce the heat produced by the boiler. What power does the heater develop under these conditions?

 


Related Discussions:- Calculate motor efficiency

Design a 4-bit universal shift register, Q. Obtain a block diagram of a shi...

Q. Obtain a block diagram of a shift-left/right register using D flip-flops. Q. Design a 4-bit universal shift register. Q. (a) Show a block diagram of an SRFF connected to s

What is non-folded network, Q. What is Non-Folded Network? Non-Folded ...

Q. What is Non-Folded Network? Non-Folded Network: In a switching network, all outlet/inlet connection may be used for inter exchange transmission. In such a case, exchange d

Write discussion on Construction and working of analog type, Write discussi...

Write discussion on Construction and working of analog type storage oscilloscope

Zener Diode, A Zener diode has the specifications VZ=6.8V and PDmax.=500mW....

A Zener diode has the specifications VZ=6.8V and PDmax.=500mW. Assume RZ=0. (a) Find the maximum allowable current iZ when the Zener diode is acting as a regulator. (b) If a sing

Magnetism, with the aid of the diagram explain the following rules that can...

with the aid of the diagram explain the following rules that can be used to determine the direction of magnetic fields around a current carrying conductor (1)cork screw rule (2)rig

Speed control of dc motor - motor control , Speed control of DC Motor ...

Speed control of DC Motor The DC  motor  are versatile motors among the  available  electrical  motors due to  their  superior  characteristics. These motors  give a smooth sp

Explain the excess three codes - bcd to decimal conversion, Explain the Exc...

Explain the Excess three codes - BCD to Decimal Conversion The Excess-3 representation of a number is based on Binary Coded Decimal. It is formed by taking the number in Binary

Simulink help, I want simulink model for carrier based pwm method

I want simulink model for carrier based pwm method

Signals, Using the audiorecorder() function in MATLAB, make a recording of ...

Using the audiorecorder() function in MATLAB, make a recording of your voice. Use a sample rate of 8kHz, 16 bits per sample, and aim to record around 2 seconds worth. Quantize th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd